At the height of the London blitz Dr Lennox Collins,pioneer of the new forensic science,is enlisted by DI Wilkins after prostitute Mary Williams is strangled and a swastika carved on her tongue. Wilkins' chief suspect is shy young Anglo-German Wilfred Ziegler,who found the body but Lennox dismisses this as Ziegler is left-handed and the killer was not.The trail leads to the Metropole club,frequented by Mary,where Lennox's new assistant Molly meets the sinister owner Danny Hastings but then two more women are killed in the same way. A rent boy places closet gay actor Ronald Terry at the scene of the last murder though Terry denies seeing anything. However Lennox and Molly are soon investigating Terry's apparent suicide - which they work out is murder. Lennox takes Hastings' DNA but is attacked by men in gas masks and,when Wilkins is taken off the case after bullying Ziegler into a confession, it looks as if Hastings has corrupt police officers in his pocket. Acting separately Lennox ...

When Detective Mortimer Shade is somehow killed in a freezer, a parasite called a grail possesses his body, revives him, but he needs blood to stay alive. His partner John Dark accepts the new situation and together they become vigilantes, judging and killing the bad guys, with Shade sucking their blood with his claw. However, Dark notes that Shade is losing the rest of his humanity and becoming a monster, being aware and afraid of the danger Shade represents to mankind and trying to stop him.

While rafting in the Bluefish River area, four college kids are attacked by the mutant cannibal hillbilly Three Finger. Only the teenager Alex succeeds in escaping running through the woods. Meanwhile, a group of dangerous criminals are transported from the West Virginia Grafton Penitentiary in a custody bus escorted by three security guards through the backwoods. When they park in a rest stop in a police station, Sheriff Carver is informed about the missing teenagers. The bus driver heads to their destination with the guards and the prisoners but a tow truck driven by Three Finger hits the bus that falls off the road. They are attacked by Three Finger and the perilous Carlo Chavez dominates the guards and the other prisoners. When they accidentally meet Alex, the girl tells how sick and threatening Three Finger is; sooner the survivals discover that Alex is telling the truth.